Electrical connectors of the type that interconnect circuitry between two circuit boards typically interconnect so called daughter boards to mother boards, or one circuit board to another parallel circuit board where the two boards are vertically stacked, one over the other. In the case of the daughter board it is usually positioned perpendicular to the mother board and includes contact pads along its edge that interconnect to its circuitry. This edge of the daughter board is received in a connector that is mounted to the motherboard. Electrical contacts are spaced within the connector housing to engage the contact pads along one or both sides of the board. These contacts include tail portions that are either received in plated through holes in the mother board or are surface mounted thereto to complete the connection to the circuitry on the mother board. Where the circuit elements of two parallel circuit boards are to be interconnected, an edge connector is employed having two spaced apart channels, each of which receives the edge of a respective circuit board. The connector, called a jumper connector, includes contact members having a spring contact element at each end, one contact element in engagement with the circuitry of one board and the other contact element in engagement with the circuitry of the other board. In both of these cases the contacts are usually pre-loaded so that adequate contact force can be achieved when the circuit boards are mated to the connector. This pre-loading requires that each contact element have an extended portion that engages and rides in a slot, usually disposed parallel to the plane of the circuit board. See, for example, U.S. Pat. No. 3,778,753 which issued Dec. 11, 1973 to Occhipinti et al. The connector of the '753 patent includes a pair of U-shaped contact members which form two rows of pairs of contact elements that engage the pads on the two parallel circuit boards. Each contact member includes a flat shank portion that is secured to the bottom floor of the connector housing and includes two relatively straight and rather long beams extending upwardly that terminate in contact element that engage the circuitry of the circuit boards. Each contact element includes a T-shaped end that is captured in a vertical track formed in the housing. As the contact member is initially inserted into the connector housing each contact element is deflected slightly away from the channel that it is being inserted into so that the T-shaped end engages the vertical track. This structure results in a substantial vertical movement of the T-shaped ends in their respective tracks when mated with the circuit boards, thereby resulting in the connector being relatively higher than would otherwise be necessary. In applications where space is at a premium, such as high density electronic packages in the portable computer and telecommunications industries, such bulky jumper connectors are unusable.
What is needed is an electrical connector for interconnecting the circuitry on two parallel circuit boards having a structure that lends itself to miniaturization and that minimizes the overall height of the connector and its encroachment onto the circuit board.